SOLUTION: Expand: (2+3i)^2

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Question 207549: Expand: (2+3i)^2
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
%282%2B3i%29%2A%282%2B3i%29 Start with the given expression.


%282%2B3i%29%5E2 Expand


%282%29%282%29%2B%282%29%283i%29%2B%283i%29%282%29%2B%283i%29%283i%29 FOIL.


4%2B6i%2B6i%2B9i%5E2 Multiply.


4%2B6i%2B6i%2B9%28-1%29 Replace i%5E2 with -1. Note: i%5E2=-1.


4%2B6i%2B6i-9 Multiply.


-5%2B12i Combine like terms.


So %282%2B3i%29%5E2=-5%2B12i.


So the expression is now in standard form a%2Bbi where a=-5 and b=12